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1-N-2-2

Page history last edited by Tashe Harris 6 years, 2 months ago

1.N.2.2 Determine if equations involving addition and subtraction are true.

In a Nutshell

First graders build on their previous work with the composition and decomposition of numbers by writing number sentences to represent a real-world or mathematical situation involving addition and subtraction. In addition, they will write a real-world problem to represent a given number sentence.

Student Actions	Teacher Actions
Develop mathematical reasoning as they determine if number sentences involving addition and subtraction are true or false and explaining their thinking to peers. Develop the ability to communicate mathematical ideas about addition and subtraction number sentences to one another through examples, models, and drawings using appropriate vocabulary such as number sentence, add, subtract, equation, true, false, sum, difference, unknown,etc. Develop accurate and appropriate procedural fluency with basic number combinations for addition and subtraction. Students can add two sides of a domino and tell a peer why their answer is true. Students can sort through true and false number sentences in small groups. Students can then discuss why some sentences were true and false, explaining what they think might have been incorrect about the false number sentences and then correcting them.	Implement tasks that promote reasoning and problem solving that invite exploration of addition and subtraction in variety of settings and contexts that are both true and false. Below are some examples of True/False statements that should also include developing understanding of the equal sign as well. 7 = 8 – 1 9 + 3 = 10 8 = 8 5 + 3 = 10 3 + 4 + 5 = 3 + 5 + 4 4 + 3 = 3 + 4 3 + 4 = 7 + 5 6 – 1 = 1 – 6 Pose purposeful questions to determine whether a number sentence is true or false. What makes this equation true or false? How did you get that? Explain why this is true/false. Does this make sense? What happened in this problem? Use and connect mathematical representations students use manipulatives to model problems and determine if they are true or false in a variety of contexts including missing variables and true addition and subtraction situations. Facilitate meaningful math discourse through number talks in whole and small group settings. Teacher should be intentional about adding in both true and untrue number sentences in relatable stories allowing students to determine accuracy and justify their thinking when solving. Different types of number stories with knowns and unknowns will encourage students to persevere and become effective problem solvers.
Key Understandings	Misconceptions
Recognize the properties of addition as they relate addition and subtraction as inverse operations. Work with number sentences to determine if a number sentence is true or false. For example, is 5 + 3 = 8 true or false? Students also work with variables by determining an unknown in a number sentence. These unknowns are found in varying positions in the number sentences, for example, 5 + = 8, and 5 = - 3, 3 + 5 = ∆	That the commutative property applies to subtraction. That the equal sign, =, means to give an answer instead of meaning, “is the same as”. ∆ = 10 - 3 is read: 3 minus 10 equals ∆. That the equal sign, =, means to give an answer instead of meaning, “is the same as” and it is always on the the right side of an equation.